Significance of Differential Characteristics in Infantile Kawasaki Disease

Abstract

Background and Objectives Immunological variability in Kawasaki disease (KD) shows age-specific differences; however, specific differences in laboratory values have not been compared between infants and non-infants with KD. We compared age-adjusted Z-values (Z) of white and red blood cells in infants with KD with those in non-infants with KD. Methods This study retrospectively investigated 192 infants and 667 non-infants recruited between 2003 and 2015 at the Korea University Hospital. Laboratory values for infants with KD and non-infants with KD were analyzed and age-unadjusted raw values (R) and age-adjusted Z for blood cells counts were determined. Results Z in infants with KD during pre-intravenous immunoglobulin (IVIG), post-IVIG, and chronic phases showed increased lymphopenia and eosinophilia, low neutrophil:lymphocyte and neutrophil:eosinophil ratios, worse anemia, increased thrombocytosis, and reduced erythrocyte sedimentation rates compared with those in non-infants with KD. The optimal cut-off value for pre-IVIG Z-hemoglobin for prediction of KD in all patients was <−0.01 (area under the curve [AUC], 0.914; sensitivity/specificity, 0.999/0.886; p=0.04). The optimal cut-off value for pre-IVIG C-reactive protein (CRP) for prediction of KD in infants compared to that in febrile control infants was >40 mg/L (AUC, 0.811; sensitivity/specificity, 0.712/0.700; p=0.04). Conclusions Laboratory characteristics enable differentiation between infants and non-infants with KD and contribute to a better understanding of changes in blood cell counts. Infants with incomplete KD can be more easily differentiated from infants with simple febrile illness using pre-IVIG Z-hemoglobin and pre-IVIG CRP values.

The Risk Prediction of Coronary Artery Lesions through the Novel Hematological Z-Values in 4 Chronological Age Subgroups of Kawasaki Disease

“…We demonstrated that the laboratory characteristics of leukocyte, neutrophil, lymphocyte, and hemoglobin in KD were different from those in FC [5]. Our study showed that the Z-values of the WBC and RBC counts in the < 6 months age subgroup in KD did not show significant differences compared with those in the corresponding age subgroups in FC.…”

“…A previous study reported that most cases of KD (>80% of cases) occur between the ages of 6 months and 5 years, and the occurrence of KD before 6 months or after 5 years of age is rare [4]. Our previous investigation showed that the risk of CAL in infantile KD throughout all phases was highly associated with lower Z-hemoglobin and thrombocytosis compared with non-infantile KD [5]. It is necessary to investigate whether there are differences in immunological reaction and CAL by the age subgroups classified according to the prevalence of KD, and it is particularly important to detect latent CAL early through useful predictors in young infants with KD.…”

“…The hematological Z-value can be a useful standard parameter through which to understand the chronological changes of WBC and RBC counts according to age, although one limitation is that ethnic differences may be present [5]. The age-adjusted Z-values for differential WBC and RBC counts can eliminate age bias because each chronological age has a different normal range (different mean and SD).…”

“…In total, 223 patients with infantile KD and 681 patients with non-infantile KD were enrolled in this study. A total of 31 children aged <6 months and 14 children aged >5 years were included in the extreme age subgroup during an additional 3-year period (from 2016 to 2018), compared to our previous study [5] Children with KD were divided into the infantile and non-infantile KD groups and further subdivided by ages of 6 months and 5 years (4 subgroups) according to rare or predominant incidences. The extreme age subgroups were defined as extreme young (EY, <6 months) and extreme old (EO, >5 years).…”

Characteristics and Indications of Kawasaki Disease Among Infants Under 6 Months

“…It had been revealed that PLT, CRP, N%, serum sodium, and albumin were all risk factors of IVIG resistance in KD (7,20,21), which were possibly indicative of more severe inflammation. Although the specific mechanism of CAL was not well-elucidated and the relationship between ages and the laboratory variables was complicated (18), the incidence of CAL in younger patients was higher with no significant difference in giant CAA and dimension of the dilated coronary artery. Our results showed a lower incidence of coronary artery dilation that was different from that reported by other studies (9,13), the divergences could be explained by coronary artery dilation definition larger than 3 mm when patients were younger than 3 years.…”